Compound Structure

Polygon feature which encompasses one or more components and represents a manmade construction that has been built for a specific purpose. Examples include a bridge, a dam, an aqueduct, and a tunnel.

Temporal filtering

The earliest and latest dates on which you can request a one-off snapshot of a date in the past for the data schema versions available for this feature type are detailed in the following table:

Data schema version	Earliest date	Latest date
1.1	29 September 2022	Ongoing
2.0	25 September 2024	Ongoing

Any data temporally filtered earlier than the specified earliest date noted above for the data schema versions may contain data inconsistencies.

Data Schema versioning

Data schema version	Launch Date	Change
1.0	29 September 2022	Initial launch of Compound Structure.
1.1	25 September 2024	Minor version increment adding classification values for Tunnels.
2.0	25 September 2024	Major version increment adding Network Over attribution, Network Under attribution and classification values for Tunnels.

More information about data schema versioning in the OS NGD Structures Theme is available from the 'Data schema versioning' page.

Feature type attributes

The following sub-sections provide details about the attributes included with this feature type, their data types in the different output formats, and other important metadata about them.

Loading OS NGD CSV files into databases

Comma-separated values (CSV) file format is universally supported for easy ingestion into all major database products. Before loading OS NGD data contained in CSV files into a database, it is necessary to create relevant tables. Data definition language (DDL) statements for PostgreSQL, SQL Server and Oracle can be accessed in our OS NGD Resources GitHub repository.

For instructions on loading CSV files, see the Getting Started with CSV guide.

osid

Primary identifier for the feature. The OSID is a Globally Unique Identifier (GUID) and requires no centralised authority to ensure uniqueness. Note that the same OSID can occur in more than one feature type when a single feature is represented multiple times in the OS NGD.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Max Length: 36

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

versiondate

Date when the version was last updated.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: false

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

versionavailablefromdate

The date this version of the feature became the latest version.

• Data Types: String (GeoJSON), DateTime (GPKG), DateTime (CSV)

• Nullable: false

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

versionavailabletodate

The date this version of the feature was superseded by an update or ceased to exist.

• Data Types: String (GeoJSON), DateTime (GPKG), DateTime (CSV)

• Nullable: true

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

changetype

The type of change that generated a new version of the feature.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Code List Name: changetypevalue
• Max Length: 50

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

geometry

Geometry for the feature.

• Data Types: Geometry (GeoJSON), Geometry (GPKG), WKT (CSV)

• Nullable: false

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

• Geometry Type: MultiPolygon

geometry_area_m2 (formerly geometry_area)

This attribute was called geometry_area in data schema version 1.0 and was renamed geometry_area_m2 from version 2.0 onward.

The measured area of the geometry in square metres.

v2.0

• Data Types: Number (GeoJSON), Float (GPKG), Real (CSV)

• Nullable: false

• Precision: 15

• Scale: 3

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: No

• Data Schema Version: 2.0

v1.1

• Data Types: Number (GeoJSON), Float (GPKG), Real (CSV)

• Nullable: false

• Precision: 15

• Scale: 6

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: No

• Data Schema Version: 1.1

geometry_evidencedate

The date on which the latest evidence was gathered to make an update if required. For example, the date of collection by a surveyor or the date third party information was received.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: true

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

geometry_updatedate

Date when the attribute was last updated.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: false

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

geometry_source

The source organisation who provided the data.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 50

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

theme

The OS NGD theme to which this feature belongs.

• Data Types: Array (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Code List Name: themevalue
• Max Length: 40

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

description

A single descriptive value intended for a quick understanding of what the feature represents.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Code List Name: compoundstructuredescriptionvalue
• Code List Version: 2.0

• Max Length: 50

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: Yes

• Data Schema Version: 1.1, 2.0

description_evidencedate

The date on which the latest evidence was gathered to make an update if required. For example, the date of collection by a surveyor or the date third party information was received.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: true

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

description_updatedate

Date when the attribute was last updated.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: false

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

description_source

The source organisation who provided the data.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Max Length: 50

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

name1_text

Name assigned to identify the feature.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 254

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: Yes

• Data Schema Version: 1.1, 2.0

name1_language

The language type associated with name1. The valid values are defined in the LanguageValue code list.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Code List Name: languagevalue
• Max Length: 3

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

name1_evidencedate

The date on which the latest evidence was gathered to make an update if required. For example, the date of collection by a surveyor or the date third party information was received.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: true

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

name1_updatedate

Date when the attribute was last updated.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: true

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

name1_source

The organisation that provided the information.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 50

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

name2_text

The alternative language name assigned to identify the feature.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 254

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: Yes

• Data Schema Version: 1.1, 2.0

name2_language

The language type associated with name2. The valid values are defined in the LanguageValue code list.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Code List Name: languagevalue
• Max Length: 3

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

name2_evidencedate

The date on which the latest evidence was gathered to make an update if required. For example, the date of collection by a surveyor or the date third party information was received.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: true

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

name2_updatedate

Date when the attribute was last updated.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: true

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

name2_source

The organisation that provided the information.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 50

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

name3_text

The proper name of a feature, populated where at least three or more names have been captured for the same feature.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 254

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: Yes

• Data Schema Version: 1.1, 2.0

name3_language

The language the name is expressed in.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Code List Name: languagevalue
• Max Length: 3

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

name3_evidencedate

The date on which the latest evidence was gathered to make an update if required. For example, the date of collection by a surveyor or the date third party information was received.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: true

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

name3_updatedate

Date when the attribute was last updated.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: true

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

name3_source

The organisation that provided the information.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 50

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

name4_text

The proper name of a feature, populated where four names have been captured for the same feature.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 254

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: Yes

• Data Schema Version: 1.1, 2.0

name4_language

The language the name is expressed in.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Code List Name: languagevalue
• Max Length: 3

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

name4_evidencedate

The date on which the latest evidence was gathered to make an update if required. For example, the date of collection by a surveyor or the date third party information was received.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: true

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

name4_updatedate

Date when the attribute was last updated.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: true

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

name4_source

The source organisation who provided the data.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 50

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

operationalstatus

An indicator of whether the feature is currently performing its original function.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Code List Name: operationalstatusvalue
• Max Length: 10

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: Yes

• Data Schema Version: 1.1, 2.0

capturespecification

Indicates the capture specification used by OS when capturing the feature. This could either be Urban, Rural or Moorland.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Code List Name: capturespecificationvalue
• Max Length: 10

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.1, 2.0

networkover

Description of the network passing over a bridge. Will be null if the network could not be determined, if the bridge has no network passing over it, or for Compound Structures that are not bridges.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Code List Name: networkoverunderbridgevalue
• Max Length: 10

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 2.0

networkunder

Description of the network passing under a bridge. Will be null if the network could not be determined, if the bridge has no network passing under it, or for Compound Structures that are not bridges.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Code List Name: networkoverunderbridgevalue
• Max Length: 10

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 2.0